Children on HD or PD with suspected or confirmed infections due to gram-positive bacteria and who are concurrently treated with standard of care antibiotics will be considered for this study. Each patient will be given a onetime dose of Cubicin (daptomycin). After receiving daptomycin, serial blood samples along with dialysis effluent and urine (obtained from non-anuric patients) will be collected to evaluate the pharmacokinetic profile of the drug.